MFEMLineValueSampler

Overview

This class performs accurate interpolation of scalar and vector quantities along a specified line using MFEM's FindPointsGSLIB gslib interpolation.

Example Input File Syntax

[VectorPostprocessors<<<{"href": "../../../syntax/VectorPostprocessors/index.html"}>>>]
  [point_sample]
    type = MFEMPointValueSampler<<<{"description": "Sample an MFEM variable at specific points.", "href": "MFEMPointValueSampler.html"}>>>
    variable<<<{"description": "The names of the variables that this VectorPostprocessor operates on"}>>> = 'concentration'
    points<<<{"description": "The points where you want to evaluate the variables"}>>> = '2.125 0 -1.375  2.125 0 1.125'
  []
[]

Input Parameters

end_pointThe ending of the line
C++ Type:libMesh::Point
Controllable:No
Description:The ending of the line
num_pointsThe number of points to sample along the line
C++ Type:unsigned int
Controllable:No
Description:The number of points to sample along the line
start_pointThe beginning of the line
C++ Type:libMesh::Point
Controllable:No
Description:The beginning of the line
variableThe names of the variables that this VectorPostprocessor operates on
C++ Type:VariableName
Unit:(no unit assumed)
Controllable:No
Description:The names of the variables that this VectorPostprocessor operates on

Required Parameters

contains_complete_historyFalseSet this flag to indicate that the values in all vectors declared by this VPP represent a time history (e.g. with each invocation, new values are added and old values are never removed). This changes the output so that only a single file is output and updated with each invocation
Default:False
C++ Type:bool
Controllable:No
Description:Set this flag to indicate that the values in all vectors declared by this VPP represent a time history (e.g. with each invocation, new values are added and old values are never removed). This changes the output so that only a single file is output and updated with each invocation
execute_onTIMESTEP_ENDThe list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html.
Default:TIMESTEP_END
C++ Type:ExecFlagEnum
Options:XFEM_MARK, FORWARD, ADJOINT, HOMOGENEOUS_FORWARD, ADJOINT_TIMESTEP_BEGIN, ADJOINT_TIMESTEP_END, NONE, INITIAL, LINEAR, LINEAR_CONVERGENCE, NONLINEAR, NONLINEAR_CONVERGENCE, POSTCHECK, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, MULTIAPP_FIXED_POINT_CONVERGENCE, FINAL, CUSTOM
Controllable:No
Description:The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html.
parallel_typeREPLICATEDSet how the data is represented within the VectorPostprocessor (VPP); 'distributed' indicates that data within the VPP is distributed and no auto communication is performed, this setting will result in parallel output within the CSV output; 'replicated' indicates that the data within the VPP is correct on processor 0, the data will automatically be broadcast to all processors unless the '_auto_broadcast' param is set to false within the validParams function.
Default:REPLICATED
C++ Type:MooseEnum
Options:DISTRIBUTED, REPLICATED
Controllable:No
Description:Set how the data is represented within the VectorPostprocessor (VPP); 'distributed' indicates that data within the VPP is distributed and no auto communication is performed, this setting will result in parallel output within the CSV output; 'replicated' indicates that the data within the VPP is correct on processor 0, the data will automatically be broadcast to all processors unless the '_auto_broadcast' param is set to false within the validParams function.
point_orderingVDIMOrdering style to use for point vector DoFs.
Default:VDIM
C++ Type:MooseEnum
Options:NODES, VDIM
Controllable:No
Description:Ordering style to use for point vector DoFs.

Optional Parameters

control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
Controllable:No
Description:Adds user-defined labels for accessing object parameters via control logic.
enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Controllable:No
Description:Set the enabled status of the MooseObject.
outputsVector of output names where you would like to restrict the output of variables(s) associated with this object
C++ Type:std::vector<OutputName>
Controllable:No
Description:Vector of output names where you would like to restrict the output of variables(s) associated with this object

Advanced Parameters

Input Files

(test/tests/mfem/vectorpostprocessors/line_value_sampler/line_value_sampler_diffusion.i)
(test/tests/mfem/kernels/nl_heattransfer.i)
(test/tests/mfem/transfers/sibling_transfers/mfem_sub_between_diffusion.i)
(test/tests/mfem/vectorpostprocessors/line_value_sampler/line_value_sampler_curlcurl.i)
(test/tests/mfem/auxkernels/2Dmagnetostatic.i)

(test/tests/mfem/vectorpostprocessors/point_value_sampler/point_value_sampler_diffusion.i)

# MFEM diffusion problem sampled with MFEMPointValueSampler.

[Mesh]
  type = MFEMMesh
  file = ../../mesh/mug.e
[]

[Problem]
  type = MFEMProblem
[]

[FESpaces]
  [H1FESpace]
    type = MFEMScalarFESpace
    fec_type = H1
    fec_order = FIRST
  []
  [HCurlFESpace]
    type = MFEMVectorFESpace
    fec_type = ND
    fec_order = FIRST
  []
[]

[Variables]
  [concentration]
    type = MFEMVariable
    fespace = H1FESpace
  []
[]

[AuxVariables]
  [concentration_gradient]
    type = MFEMVariable
    fespace = HCurlFESpace
  []
[]

[AuxKernels]
  [grad]
    type = MFEMGradAux
    variable = concentration_gradient
    source = concentration
    execute_on = TIMESTEP_END
  []
[]

[ICs]
  [diffused_ic]
    type = MFEMScalarIC
    coefficient = one
    variable = concentration
  []
[]

[Functions]
  [one]
    type = ParsedFunction
    expression = 1.0
  []
[]

[BCs]
  [bottom]
    type = MFEMScalarDirichletBC
    variable = concentration
    boundary = 'bottom'
    coefficient = 1.0
  []
  [top]
    type = MFEMScalarDirichletBC
    variable = concentration
    boundary = 'top'
  []
[]

[FunctorMaterials]
  [Substance]
    type = MFEMGenericFunctorMaterial
    prop_names = diffusivity
    prop_values = 1.0
    block = 'the_domain'
  []
[]

[Kernels]
  [diff]
    type = MFEMDiffusionKernel
    variable = concentration
    coefficient = diffusivity
  []
[]

[Preconditioner]
  [boomeramg]
    type = MFEMHypreBoomerAMG
  []
  [jacobi]
    type = MFEMOperatorJacobiSmoother
  []
[]

[Solver]
  type = MFEMHypreGMRES
  preconditioner = boomeramg
  l_tol = 1e-16
  l_max_its = 1000
[]

[VectorPostprocessors]
  [point_sample]
    type = MFEMPointValueSampler
    variable = 'concentration'
    points = '2.125 0 -1.375  2.125 0 1.125'
  []
[]

[Executioner]
  type = MFEMSteady
  device = cpu
[]

[Outputs]
  execute_on = 'timestep_end'
  csv = true
[]

(test/tests/mfem/vectorpostprocessors/line_value_sampler/line_value_sampler_diffusion.i)

# MFEM diffusion problem sampled with MFEMLineValueSampler.

[Mesh]
  type = MFEMMesh
  file = ../../mesh/mug.e
[]

[Problem]
  type = MFEMProblem
[]

[FESpaces]
  [H1FESpace]
    type = MFEMScalarFESpace
    fec_type = H1
    fec_order = FIRST
  []
  [HCurlFESpace]
    type = MFEMVectorFESpace
    fec_type = ND
    fec_order = FIRST
  []
[]

[Variables]
  [concentration]
    type = MFEMVariable
    fespace = H1FESpace
  []
[]

[AuxVariables]
  [concentration_gradient]
    type = MFEMVariable
    fespace = HCurlFESpace
  []
[]

[AuxKernels]
  [grad]
    type = MFEMGradAux
    variable = concentration_gradient
    source = concentration
    execute_on = TIMESTEP_END
  []
[]

[ICs]
  [diffused_ic]
    type = MFEMScalarIC
    coefficient = one
    variable = concentration
  []
[]

[Functions]
  [one]
    type = ParsedFunction
    expression = 1.0
  []
[]

[BCs]
  [bottom]
    type = MFEMScalarDirichletBC
    variable = concentration
    boundary = 'bottom'
    coefficient = 1.0
  []
  [top]
    type = MFEMScalarDirichletBC
    variable = concentration
    boundary = 'top'
  []
[]

[FunctorMaterials]
  [Substance]
    type = MFEMGenericFunctorMaterial
    prop_names = diffusivity
    prop_values = 1.0
    block = 'the_domain'
  []
[]

[Kernels]
  [diff]
    type = MFEMDiffusionKernel
    variable = concentration
    coefficient = diffusivity
  []
[]

[Preconditioner]
  [boomeramg]
    type = MFEMHypreBoomerAMG
  []
  [jacobi]
    type = MFEMOperatorJacobiSmoother
  []
[]

[Solver]
  type = MFEMHypreGMRES
  preconditioner = boomeramg
  l_tol = 1e-16
  l_max_its = 1000
[]

[VectorPostprocessors]
  [line_sample]
    type = MFEMLineValueSampler
    variable = 'concentration'
    start_point = '2.125 0 -2.375'
    end_point = '2.125 0 2.625'
    num_points = 11
  []
[]

[Executioner]
  type = MFEMSteady
  device = cpu
[]

[Outputs]
  execute_on = 'timestep_end'
  csv = true
[]

(test/tests/mfem/kernels/nl_heattransfer.i)

[Problem]
  type = MFEMProblem
[]

[Mesh]
  type = MFEMMesh
  file = ../mesh/stacked_hexes.e
[]

[FESpaces]
  [H1FESpace]
    type = MFEMScalarFESpace
    fec_type = H1
    fec_order = FIRST
  []
[]

[Variables]
  [temperature]
    type = MFEMVariable
    fespace = H1FESpace
  []
[]

[ICs]
  [temperature_ic]
    type = MFEMScalarIC
    coefficient = 200.0
    variable = temperature
  []
[]

[Functions]
  [T_inf]
    type = MFEMParsedFunction
    expression = 'temperature + 1'
    symbol_names = 'temperature'
    symbol_values = 'temperature'
  []
  [htc]
    type = MFEMParsedFunction
    expression = 'temperature/100 + 1'
    symbol_names = 'temperature'
    symbol_values = 'temperature'
  []
  [dhtc_dT]
    type = MFEMParsedFunction
    expression = '1 / 100'
    symbol_names = 'temperature'
    symbol_values = 'temperature'
  []
[]

[Kernels]
  [dT_dt]
    type = MFEMTimeDerivativeMassKernel
    variable = temperature
  []
  [diffusion]
    type = MFEMDiffusionKernel
    variable = temperature
  []
[]

[BCs]
  active = nonlinear
  [nonlinear]
    type = MFEMNLConvectiveHeatFluxBC
    variable = temperature
    boundary = 'right'
    T_infinity = T_inf
    heat_transfer_coefficient = htc
    d_heat_transfer_dT_coefficient = dhtc_dT
  []
  [linearized]
    type = MFEMNLConvectiveHeatFluxBC
    variable = temperature
    boundary = 'right'
    T_infinity = 201.0
    heat_transfer_coefficient = 3.0
    d_heat_transfer_dT_coefficient = 0.0
  []
[]

[VectorPostprocessors]
  [line_sample]
    type = MFEMLineValueSampler
    variable = 'temperature'
    start_point = '0.0 0.5 0.5'
    end_point = '1.0 0.5 0.5'
    num_points = 3
    execute_on = TIMESTEP_END
  []
[]

[Solver]
   type = MFEMMUMPS
   print_level = 0
[]

[Executioner]
  type = MFEMTransient
  device = cpu
  assembly_level = legacy
  dt = 1
  num_steps = 3
  nl_max_its = 150

  nl_abs_tol = 1e-12
  print_level = 1
[]

[Outputs]
  [ParaViewDataCollection]
    type = MFEMParaViewDataCollection
    file_base = OutputData/NLHeatTransfer
    vtk_format = ASCII
  []
  [CSV]
    type = CSV
    file_base = OutputData/NLHeatTransfer
    time_step_interval = 3
  []
[]

(test/tests/mfem/transfers/sibling_transfers/mfem_sub_between_diffusion.i)

[Problem]
  type = MFEMProblem
  solve = false
[]

[Mesh]
  type = MFEMMesh
  file = ../../mesh/square_quad9.e
[]

[FESpaces]
  [H1FESpace]
    type = MFEMScalarFESpace
    fec_type = H1
    fec_order = FIRST
  []
  [L2FESpace]
    type = MFEMScalarFESpace
    fec_type = L2
    fec_order = CONSTANT
  []
[]

[AuxVariables]
  [sent_nodal]
    type = MFEMVariable
    fespace = H1FESpace
  []
  [received_nodal]
    type = MFEMVariable
    fespace = H1FESpace
  []
  [sent_elem]
    type = MFEMVariable
    fespace = L2FESpace
  []
  [received_elem]
    type = MFEMVariable
    fespace = L2FESpace
  []
[]

[Functions]
  [sent_nodal_var_func]
    type = ParsedFunction
    expression = '1 + 2*x*x + 3*y*y*y'
  []
  [sent_elem_var_func]
    type = ParsedFunction
    expression = '2 + 2*x*x + 3*y*y*y'
  []
  [received_nodal_var_func]
    type = ParsedFunction
    expression = '3 + 2*x*x + 3*y*y*y'
  []
  [received_elem_var_func]
    type = ParsedFunction
    expression = '4 + 2*x*x + 3*y*y*y'
  []
[]

[ICs]
  [sent_nodal_var_ic]
    type = MFEMScalarIC
    variable = 'sent_nodal'
    coefficient = sent_nodal_var_func
  []
  [sent_elem_var_ic]
    type = MFEMScalarIC
    variable = 'sent_elem'
    coefficient = sent_elem_var_func
  []
  [received_nodal_var_ic]
    type = MFEMScalarIC
    variable = 'received_nodal'
    coefficient = -1
  []
  [received_elem_var_ic]
    type = MFEMScalarIC
    variable = 'received_elem'
    coefficient = -1
  []

[]

[Executioner]
  type = MFEMTransient
  num_steps = 1
  device = cpu
[]

[VectorPostprocessors]
  [nodal_sample]
    type = MFEMLineValueSampler
    variable = 'received_nodal'
    start_point = '0.0 0.0 0.0'
    end_point = '1.0 1.0 0.0'
    num_points = 14
    execute_on = TIMESTEP_END
  []
  [elem_sample]
    type = MFEMLineValueSampler
    variable = 'received_elem'
    start_point = '0.0 0.0 0.0'
    end_point = '1.0 1.0 0.0'
    num_points = 14
    execute_on = TIMESTEP_END
  []
[]

[Outputs]
  csv = true
  inactive = ParaViewDataCollection
  [ParaViewDataCollection]
    type = MFEMParaViewDataCollection
    vtk_format = ASCII
  []
[]

(test/tests/mfem/vectorpostprocessors/line_value_sampler/line_value_sampler_curlcurl.i)

# Definite Maxwell problem solved with Nedelec elements of the first kind
# based on MFEM Example 3. Sampled with MFEMLineValueSampler.

[Mesh]
  type = MFEMMesh
  file = ../../mesh/small_fichera.mesh
[]

[Problem]
  type = MFEMProblem
[]

[FESpaces]
  [HCurlFESpace]
    type = MFEMVectorFESpace
    fec_type = ND
    fec_order = FIRST
  []
  [HDivFESpace]
    type = MFEMVectorFESpace
    fec_type = RT
    fec_order = CONSTANT
  []
[]

[Variables]
  [e_field]
    type = MFEMVariable
    fespace = HCurlFESpace
  []
[]

[AuxVariables]
  [db_dt_field]
    type = MFEMVariable
    fespace = HDivFESpace
  []
[]

[AuxKernels]
  [curl]
    type = MFEMCurlAux
    variable = db_dt_field
    source = e_field
    scale_factor = -1.0
    execute_on = TIMESTEP_END
  []
[]

[Functions]
  [exact_e_field]
    type = ParsedVectorFunction
    expression_x = 'sin(kappa * y)'
    expression_y = 'sin(kappa * z)'
    expression_z = 'sin(kappa * x)'

    symbol_names = kappa
    symbol_values = 3.1415926535
  []

  [forcing_field]
    type = ParsedVectorFunction
    expression_x = '(1. + kappa * kappa) * sin(kappa * y)'
    expression_y = '(1. + kappa * kappa) * sin(kappa * z)'
    expression_z = '(1. + kappa * kappa) * sin(kappa * x)'

    symbol_names = kappa
    symbol_values = 3.1415926535
  []
[]

[BCs]
  [tangential_E_bdr]
    type = MFEMVectorTangentialDirichletBC
    variable = e_field
    vector_coefficient = exact_e_field
  []
[]

[Kernels]
  [curlcurl]
    type = MFEMCurlCurlKernel
    variable = e_field
  []
  [mass]
    type = MFEMVectorFEMassKernel
    variable = e_field
  []
  [source]
    type = MFEMVectorFEDomainLFKernel
    variable = e_field
    vector_coefficient = forcing_field
  []
[]

[Preconditioner]
  [ams]
    type = MFEMHypreAMS
    fespace = HCurlFESpace
  []
[]

[Solver]
  type = MFEMHypreGMRES
  preconditioner = ams
  l_tol = 1e-6
[]

[VectorPostprocessors]
  [line_sample]
    type = MFEMLineValueSampler
    variable = 'e_field'
    start_point = '1 1 -1'
    end_point = '1 1 1'
    num_points = 11
  []
[]


[Executioner]
  type = MFEMSteady
  device = cpu
[]

[Outputs]
  execute_on = 'timestep_end'
  csv = true
[]

(test/tests/mfem/auxkernels/2Dmagnetostatic.i)

[Mesh]
    type = MFEMMesh
    file = ../mesh/hinomaru.e
[]

[Problem]
    type = MFEMProblem
[]

[FESpaces]
 [H1FESpace]
   type = MFEMScalarFESpace
   fec_type = H1
   fec_order = FIRST
 []
 [HCurlFESpace]
    type = MFEMVectorFESpace
    fec_type = ND
    fec_order = FIRST
  []
  #For compatible pairing H1 order p -> ND order p -> RT order p-1
  [RTFESpace]
    type = MFEMVectorFESpace
    fec_type = RT
    fec_order = CONSTANT
  []
   [L2FESpace]
    type = MFEMScalarFESpace
    fec_type = L2
    fec_order = CONSTANT
    basis = GaussLegendre
  []
[]

[Variables]
   [Az]
    type = MFEMVariable
    fespace = H1FESpace
  []
[]

[FunctorMaterials]
  [J_wire]
    type = MFEMGenericFunctorMaterial
    prop_names = J_source
    prop_values = 8.0
    block = wire
  []
[]

[AuxVariables]
  [J]
    type = MFEMVariable
    fespace = L2FESpace
  []
  [gradAz]
    type = MFEMVariable
    fespace = HCurlFESpace
  []
  [B]
    type = MFEMVariable
    fespace = RTFESpace
  []
[]

[Kernels]
  [diffusion]
    type = MFEMDiffusionKernel
    variable = Az
  []
  [source]
    type = MFEMDomainLFKernel
    variable = Az
    coefficient = J_source
  []
[]

[AuxKernels]
  [J]
    type = MFEMScalarProjectionAux
    variable = J
    coefficient = J_source
  []
  [gradAz]
    type = MFEMGradAux
    variable = gradAz
    source = Az
  []
  [B_from_gradAz]
    type = MFEMNDtoRTAux
    variable = B
    source = gradAz
    scale_factor = 1.0
  []
[]

[BCs]
  [essential]
    type = MFEMScalarDirichletBC
    variable = Az
    boundary = outer
    coefficient = 1
  []
[]

[Preconditioner]
  [boomeramg]
    type = MFEMHypreBoomerAMG
  []
[]

[Solver]
  type = MFEMHyprePCG
  preconditioner = boomeramg
  l_tol = 1e-8
[]

[VectorPostprocessors]
  [line_sample]
    type = MFEMLineValueSampler
    variable = 'B'
    start_point = '0 2 0'
    end_point = '0 -2 0'
    num_points = 10
  []
[]

[Executioner]
  type = MFEMSteady
[]

[Outputs]
  [ReportedPostprocessors]
    type = CSV
    file_base = 2DMagnetostatic
  []
[]

Overview
Example Input File Syntax
Input Parameters
Input Files